function Scroller(name) {
	Scroller.count = (Scroller.count || 0) + 1;
    this.name = name;
	this.current = 0;
}


Scroller.prototype = {
    next: function(){
        this.current++;
		console.log('next().current'+this.current);
    },
    previous: function(){
		this.current--;
        console.log('previous().current'+this.current);
    },
	
};

var reward = new Scroller('reward');
reward.next();
reward.previous();